This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Patients in the critical care setting require rapid, accurate, and non-invasive monitoring of blood loss, blood flow, changes in oxygen delivery &consumption, and response to resuscitation. Moreover, patients experiencing traumatic injuries, such as from natural disasters, automobile accidents and crime, must be quickly triaged according to injury severity in order to optimize rescue resources that maximize the delivery of life-saving care. The purpose of this proposal is to develop and apply non-invasive Diffuse Optical Spectroscopy (DOS) monitoring devices for the diagnosis and treatment of common traumatic injuries in both critical care (i.e., intensive care, trauma physicians) and field-deployed (i.e., ambulances, first responders) settings. These devices would provide physicians and care takers with non-invasive physiological monitoring capabilities equal to or superior to what is currently available in standard practice, yet be available in either hospital or non-hospital environments. We propose to explore the application of non-invasive near-infrared (NIR, 650-1000 nm) optical sensors to provide early information about the status of common traumatic injuries to improve resuscitation and treatment. The DOS devices will be tested in both humans and animals to provide a better understanding of the physiological origins of DOS-detected signals, especially in the context of improving care and diagnosis.